Various embodiments of closure caps of the type in question are known, such as in particular closure caps which, on the inner side of the cap base, have a central closure stopper, formed integrally on the base, for a mouthpiece opening.
Among known closures of the above-mentioned kind, compare for example DE 196 16 000 A1 and SU 1 671 537 A1, the closure stopper which is rotatable relative to the cap base is not usable for mouthpiece openings of the associated container which are disposed non-rotationally symmetrically or somewhat eccentrically with respect to the central axis of rotation of the cap base.
With regard to the prior art mentioned, the object of the invention in respect of the closure cap is seen in the provision of a closure cap with a closure stopper which is rotatable relative to a closure cap base and which is also usable in the case of non-rotationally symmetrical mouthpiece openings and/or eccentric disposition of a mouthpiece opening.
In regard to the combination of closure cap and receiving vessel, reference to the state of the art is made for example to U.S. Pat. No. 6,550,647 B1. From this, it is not however already known to provide a rotary closure cap with a central axis of rotation.